10 ms·

This clearly spells the beginning of the end for transistor scaling. If every node makes the reliability worse, eventually the lifetime gets too short and you'r

by zrm 6y ago

This clearly spells the beginning of the end for transistor scaling. If every node makes the reliability worse, eventually the lifetime gets too short and you're through. The interesting question is going to be how much faster the unreliable parts are than the more reliable nodes once we're at the limit. If they're only 30% faster then in many cases that's a small price to pay for reliability. If they're 30 times faster then what you want is an increase in modularity and standardization, so that the chip that wears out every year can be a cheap fungible commodity part that you can replace without having to buy a new chassis, screen or battery.

tomxor 6y ago
>This clearly spells the beginning of the end for transistor scaling. If every node makes the reliability worse, eventually the lifetime gets too short and you're through. Transistor scaling (dennard scaling) already ended over a decade ago. Even up to that point there have been a variety of reliability challenges at each shrink, some revisited again and again requiring different techniques at each level. We haven't been making significant progress over the last decade in terms of process size, instead we're just shuffling towards the edge of a cliff (single atoms), the closer we get the more extreme the challenges will get with less return. We don't have a long road ahead with gradually decreasing reliability, we are already at the end of the road, we aren't going to get much closer to the crumbly bits if it's not worth it.
- CyberDildonics 6y ago
  10 years ago 32nm was at the cutting edge. Transistor counts have risen by around 9x in that time frame.
  - tomxor 6y ago
    Transistor count is the wrong metric because we've been increasing die area as well as shrinking process nodes... It's not sustainable to keep increasing die areas, so it's not a pivot for moores law.
    - CyberDildonics 6y ago
      Moore's law is about transistor count. Not only that but you are saying the exact opposite in reply to someone else, claiming that process node sizes don't matter.
      - tomxor 6y ago
        Moores law is about the rate of transistor count AND the implications. If you read Moore's paper you will find the context in which the definition resides is based on transistor scale, and the implication was even explicitly expressed in the very same paper by Moore - He observed that transistor doubling by reduced transistor scale gave faster clock at the same power density for the same die area. This is no longer true, we are barely still reducing transistor scale (but no longer uniformly), and no longer gain any of the other benefits due to the break down of Dennard scaling, coincidentally at the same time it became difficult to continue to reduce transistor channel scale.
        CyberDildonics 6y ago
        > rate of transistor count That doesn't really make sense. It was actually about transistor count and cost. > faster clock at the same power density That's Dennard scaling as someone already mentioned to you You said: > Transistor scaling (dennard scaling) Those are two different things. You also said: > We haven't been making significant progress over the last decade in terms of process size, This is false by any reasonable definition, since as has already been said by multiple people, transistors are a fraction of the size they were ten years ago and the density has gone up considerably. > coincidentally at the same time it became difficult to continue to reduce transistor channel scale. Frequencies did not go up, but transistors shrunk, I'm not sure why you keep trying to state otherwise. How do you explain the enormous rise in transistor count and process shrinkage over the last decade? You are literally stating something that is false and not even backing up what you are saying with any information at all.
        tomxor 6y ago
- Veedrac 6y ago
  You're mixing up terms here. Dennard scaling is the claim that power density stays constant with node shrinks. This has failed, but transistor scaling, as in the Moore's Law progression of transistors getting smaller in size, has not, and will continue to run for at least a little while longer.
  - tomxor 6y ago
    I think you are correct, technically the end of Dennard scaling is separate. > This has failed, but transistor scaling [...] has not Not entirely true, around the same time Dennard scaling ended, transistor channel length scaling also slowed down significantly (Although I don't know if they are directly related). It's not a short topic and i'm no expert, but the summary is that process node name values no longer directly relate to transistor dimensions, and scaling has become more "strategic". In my mind the end of Dennard scaling marked the beginning of the end of the road. The challenges are becoming more fundamental and yet process node reduction no longer yields the same benefits - meanwhile it's becoming realistic to count cross sectional areas in terms of numbers of atoms... the road really is short. Not that we wont find another road ;)
    - Veedrac 6y ago
      Here's my transistor scaling chart. TSMC 5nm should be coming this year, with 1.8x scaling. So my numbers say we haven't stalled yet. https://docs.google.com/spreadsheets/d/1NNOqbJfcISFyMd0EsSrhppW7PT6GCfnrVGhxhLA5PVw https://docs.google.com/spreadsheets/d/1NNOqbJfcISFyMd0EsSrh...
      - tomxor 6y ago
        But those numbers are process node name value, as I said they no longer directly relate to transistor channel length. Transistors are still shrinking by some measures, but not in the same simple way that one dimensional process node names make it appear.
        Veedrac 6y ago

by zrm 6y ago

tomxor 6y ago

>This clearly spells the beginning of the end for transistor scaling. If every node makes the reliability worse, eventually the lifetime gets too short and you're through. Transistor scaling (dennard scaling) already ended over a decade ago. Even up to that point there have been a variety of reliability challenges at each shrink, some revisited again and again requiring different techniques at each level. We haven't been making significant progress over the last decade in terms of process size, instead we're just shuffling towards the edge of a cliff (single atoms), the closer we get the more extreme the challenges will get with less return. We don't have a long road ahead with gradually decreasing reliability, we are already at the end of the road, we aren't going to get much closer to the crumbly bits if it's not worth it.

CyberDildonics 6y ago
10 years ago 32nm was at the cutting edge. Transistor counts have risen by around 9x in that time frame.
- tomxor 6y ago
  Transistor count is the wrong metric because we've been increasing die area as well as shrinking process nodes... It's not sustainable to keep increasing die areas, so it's not a pivot for moores law.
  - CyberDildonics 6y ago
    Moore's law is about transistor count. Not only that but you are saying the exact opposite in reply to someone else, claiming that process node sizes don't matter.
    - tomxor 6y ago
      Moores law is about the rate of transistor count AND the implications. If you read Moore's paper you will find the context in which the definition resides is based on transistor scale, and the implication was even explicitly expressed in the very same paper by Moore - He observed that transistor doubling by reduced transistor scale gave faster clock at the same power density for the same die area. This is no longer true, we are barely still reducing transistor scale (but no longer uniformly), and no longer gain any of the other benefits due to the break down of Dennard scaling, coincidentally at the same time it became difficult to continue to reduce transistor channel scale.
      - CyberDildonics 6y ago
        > rate of transistor count That doesn't really make sense. It was actually about transistor count and cost. > faster clock at the same power density That's Dennard scaling as someone already mentioned to you You said: > Transistor scaling (dennard scaling) Those are two different things. You also said: > We haven't been making significant progress over the last decade in terms of process size, This is false by any reasonable definition, since as has already been said by multiple people, transistors are a fraction of the size they were ten years ago and the density has gone up considerably. > coincidentally at the same time it became difficult to continue to reduce transistor channel scale. Frequencies did not go up, but transistors shrunk, I'm not sure why you keep trying to state otherwise. How do you explain the enormous rise in transistor count and process shrinkage over the last decade? You are literally stating something that is false and not even backing up what you are saying with any information at all.
        tomxor 6y ago
Veedrac 6y ago
You're mixing up terms here. Dennard scaling is the claim that power density stays constant with node shrinks. This has failed, but transistor scaling, as in the Moore's Law progression of transistors getting smaller in size, has not, and will continue to run for at least a little while longer.
- tomxor 6y ago
  I think you are correct, technically the end of Dennard scaling is separate. > This has failed, but transistor scaling [...] has not Not entirely true, around the same time Dennard scaling ended, transistor channel length scaling also slowed down significantly (Although I don't know if they are directly related). It's not a short topic and i'm no expert, but the summary is that process node name values no longer directly relate to transistor dimensions, and scaling has become more "strategic". In my mind the end of Dennard scaling marked the beginning of the end of the road. The challenges are becoming more fundamental and yet process node reduction no longer yields the same benefits - meanwhile it's becoming realistic to count cross sectional areas in terms of numbers of atoms... the road really is short. Not that we wont find another road ;)
  - Veedrac 6y ago
    Here's my transistor scaling chart. TSMC 5nm should be coming this year, with 1.8x scaling. So my numbers say we haven't stalled yet. https://docs.google.com/spreadsheets/d/1NNOqbJfcISFyMd0EsSrhppW7PT6GCfnrVGhxhLA5PVw https://docs.google.com/spreadsheets/d/1NNOqbJfcISFyMd0EsSrh...
    - tomxor 6y ago
      But those numbers are process node name value, as I said they no longer directly relate to transistor channel length. Transistors are still shrinking by some measures, but not in the same simple way that one dimensional process node names make it appear.
      - Veedrac 6y ago